Can a kidney with a Renal Cell Carcinoma (RCC) lesion be transplanted?

Transplantation of Kidneys with RCC Lesions

Donor kidneys with small RCC lesions may be transplanted if the tumor is small (<2-4 cm) and complete excision with clear margins is possible, following a case-by-case evaluation. 1, 2

Criteria for Transplanting Kidneys with RCC

Size and Characteristics

• Small RCC lesions (<2-4 cm) may be acceptable for transplantation 2
• Bosniak I cysts can be left in the donor kidney 1
• Bosniak II cysts require thorough assessment for solid components, septations, and calcifications 1
• High-grade Bosniak cysts (III or higher) or small (T1a) RCC may be acceptable on a case-by-case basis 1

Surgical Management

• Complete excision with clear margins is mandatory before transplantation 2, 3
• Back-table tumor excision is the standard approach for incidentally discovered small RCCs 4
• Partial nephrectomy techniques should be used to preserve maximum renal function 2

Evidence Supporting This Approach

The OPTN Disease Transmission Advisory Committee reviewed 147 cases of donor kidneys with known or suspected RCC at the time of transplant and found:

• 21 kidneys were transplanted after tumor excision
• 47 contralateral kidneys were transplanted
• 198 non-renal organs were transplanted
• No cases of RCC transmission were documented in any of these recipients 3

Case reports further support this approach, showing successful outcomes with small, incidentally discovered RCCs that were completely excised before transplantation 5.

Risk Considerations

Transmission Risk

• Cancer transmission from donors is rare (1-2 cases per 10,000 organ transplant recipients) 1
• Transmission risk varies by cancer type, with in situ cancers having <0.1% risk 1
• RCC transmission appears extremely low when proper selection criteria and surgical management are followed 3

Post-Transplant Monitoring

• Regular imaging follow-up is recommended, though no cost-effective screening protocol has been established specifically for RCC after transplantation 2
• The median time from transplantation to cancer diagnosis (for transmitted cancers) is approximately 8 months (IQR 3-13 months) 1

Decision-Making Process

1. Evaluate tumor size (<2-4 cm is potentially acceptable)
2. Confirm complete excision with clear margins is possible
3. Assess tumor histology (favorable pathology is preferred)
4. Consider the urgency of transplantation for the recipient
5. Implement a shared decision-making approach with the recipient, providing clear information about the potential risks 1

Pitfalls to Avoid

• Failing to thoroughly assess the tumor characteristics before transplantation
• Incomplete excision of the tumor before transplantation
• Inadequate follow-up imaging after transplantation
• Not considering the risk-benefit ratio for individual recipients, particularly those with long waiting times on dialysis 1

This approach helps expand the donor pool while maintaining safety, as the risk of death while waiting for a kidney transplant may outweigh the minimal risk of tumor transmission when proper protocols are followed 1, 3.